Results of posterior lumbar fusion have frequently been compromised by residuals from muscular and neurovascular disruption accompanying anthrodesis. An approach along the lateral aspect of the multifidus avoids disruption of the dorsal lumbar musculature and allows for segmental pedicle fixation without disturbing the neurovascular supply to the erector spinae or multifidus. Detachment of the segmental insertion of the multifidus to the mamillary process provides access for a microsurgical transforaminal interbody fusion.
Present techniques of lumbar anthrodesis including instrumentation and interbody fusion provide a reasonable expectation of fusion with surgery, however, outcomes remain limited by pain and adjacent segment failure. To the extent this results from fusion it may be unavoidable. Limitations from denervation, devascularization and disconnection of lumbar musculature and the disruption of musculoskeletal integrity of adjacent segments may be largely avoidable.
There is therefore a long felt, but unsolved need for a method and device in order to perform an instrumented lumbar arthrodesis with a minimal approach which spares the lumbar muscles from surgical disruption.